Notices
1997 - 2003 F150 1997-2003 F150, 1997-1999 F250LD, 7700 & 2004 F150 Heritage
Sponsored by:
Sponsored by: Auxito

No heat

Thread Tools
 
Search this Thread
 
Old Dec 10, 2020 | 06:47 PM
  #1  
UncleBuck18's Avatar
UncleBuck18
Thread Starter
|
New User
Joined: Nov 2020
Posts: 11
Likes: 0
No heat

I have a 2001 F150 with the 4.6 engine. I replaced the thermostat and the blend door IS working properly, and I flushed the heater core and I still have no heat. What else could this be?
 
Reply
Old Dec 10, 2020 | 07:21 PM
  #2  
projectSHO89's Avatar
projectSHO89
Hotshot
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Jan 2004
Posts: 19,760
Likes: 1,079
From: St Louis
Did you check for hot coolant flow through the heater core?

 
Reply
Old Dec 10, 2020 | 07:39 PM
  #3  
UncleBuck18's Avatar
UncleBuck18
Thread Starter
|
New User
Joined: Nov 2020
Posts: 11
Likes: 0
Yeah, they both get hot over time
 
Reply
Old Dec 10, 2020 | 07:42 PM
  #4  
projectSHO89's Avatar
projectSHO89
Hotshot
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Jan 2004
Posts: 19,760
Likes: 1,079
From: St Louis
How hot over how much time?

 
Reply
Old Dec 10, 2020 | 08:02 PM
  #5  
bbsitum's Avatar
bbsitum
More Turbo
15 Year Member
Photogenic
Liked
Loved
Joined: Apr 2009
Posts: 657
Likes: 25
Heat **** cracked or worn out. I slid piece of aluminum in and work since. I always tough people check that first.
 
Reply
Old Dec 11, 2020 | 09:59 AM
  #6  
alloro's Avatar
alloro
Fleet Owner
15 Year Member
Shutterbug
Liked
Loved
Joined: Apr 2008
Posts: 24,316
Likes: 5,127
From: 0,0,1
Club FTE Gold Member
Originally Posted by UncleBuck18
Yeah, they both get hot over time
Once the engine is up to full temperature those hoses should be too hot to hold. If you can hold onto them they're not hot enough.
 
Reply
Old Dec 11, 2020 | 10:51 AM
  #7  
UncleBuck18's Avatar
UncleBuck18
Thread Starter
|
New User
Joined: Nov 2020
Posts: 11
Likes: 0
Between 10-15 minutes the inlet and outlet hose gets very hot to the touch, and I’ve noticed when I drive with both heat and air off and I turn it on heat it will blow a rush off hot air but then it gets back cold
 
Reply
Old Dec 11, 2020 | 11:52 AM
  #8  
formerjeepguy's Avatar
formerjeepguy
Mountain Pass
Joined: Apr 2017
Posts: 170
Likes: 9
What does your coolant look like and has it been changed regularly? Has it ever been brown? Has it been run on tap water alone?

I'm wondering if the impeller blades on the water pump have rusted away to nothing.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-1

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-2

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-3

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-4

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-5

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-6

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-7

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-8

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-9

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
Old Dec 11, 2020 | 01:05 PM
  #9  
UncleBuck18's Avatar
UncleBuck18
Thread Starter
|
New User
Joined: Nov 2020
Posts: 11
Likes: 0
Coolant looks like a nice lime green
 
Reply
Old Dec 11, 2020 | 01:10 PM
  #10  
projectSHO89's Avatar
projectSHO89
Hotshot
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Jan 2004
Posts: 19,760
Likes: 1,079
From: St Louis
and I’ve noticed when I drive with both heat and air off and I turn it on heat it will blow a rush off hot air but then it gets back cold
At that point and with the blower still on high, check the temperature of the hoses.

Your basic symptom is of insufficient hot coolant in or passing through the core. Turning off the blower allows it to accumulate in the core and plenum. You need to determine whether or not here is a very substantial drop in the temperature of the outlet.
 
Reply
Old Dec 11, 2020 | 05:27 PM
  #11  
UncleBuck18's Avatar
UncleBuck18
Thread Starter
|
New User
Joined: Nov 2020
Posts: 11
Likes: 0
So should I try flushing the heater core back out again? If the temp on the outlet hose decreases after the rush of hot air?
 
Reply
Old Dec 12, 2020 | 07:08 AM
  #12  
formerjeepguy's Avatar
formerjeepguy
Mountain Pass
Joined: Apr 2017
Posts: 170
Likes: 9
Originally Posted by UncleBuck18
So should I try flushing the heater core back out again? If the temp on the outlet hose decreases after the rush of hot air?
you can try, but if your water pump isn't working right you won't get enough coolant flow through the heater core.
 
Reply
Old Dec 13, 2020 | 10:01 AM
  #13  
alloro's Avatar
alloro
Fleet Owner
15 Year Member
Shutterbug
Liked
Loved
Joined: Apr 2008
Posts: 24,316
Likes: 5,127
From: 0,0,1
Club FTE Gold Member
Originally Posted by UncleBuck18
So should I try flushing the heater core back out again? If the temp on the outlet hose decreases after the rush of hot air?
Like projectSHO89 said above, you need to feel the hoses again after the initial blast of heat goes away and the air gets cool again. If one hose is hot and the other cold you have a blockage in the heater core. If both are hot you have a blend door issue or scale build-up on the inside of the heater core.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
cwalsh540
1997 - 2003 F150
5
Dec 14, 2020 01:43 PM
mlelah
Explorer, Sport Trac, Mountaineer & Aviator
26
Jan 10, 2015 02:27 PM
10actuxedo
1997 - 2003 F150
2
Nov 16, 2014 07:55 AM
COhunter
Cooling, Heating, Ventilation & A/C
5
Aug 14, 2003 07:05 PM
Mudinyureyes
1978 - 1996 Big Bronco
5
Nov 18, 2002 12:56 AM




All times are GMT -5. The time now is 06:40 AM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-1
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-2
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-3
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-4
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-5
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-6
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-7
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-8
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-9
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE